Definition: You are given a question on high school microeconomics. You are also given 4 answer options (associated with "A", "B", "C", "D"), out of which only one is correct. You need to answer the question by selecting the correct option. You should only answer with the choice letter, not the whole answer.
Input: Which of the following best exemplifies economies of scale?
(A)As a firm's output decreases, average costs for production decrease. (B)As a firm's output increases, average costs for production increase. (C)As a firm's inputs triple, its output quadruples. (D)As a firm's inputs triple, its output doubles.

C